The present invention relates to an under-water cable burying device to bury under-water cable which are laid under-water in the sea bed.
The recent trend has been to construct cables buried in the sea bed or in the river bed so as to avoid breakage of cables caused by anchors of vessels or fish nets. In the prior art, a device having a sea-bed trenching device of either the plow type or the water jet type is towed by a mother ship to bury such cables. In such burying device of plow-type, when the cables carried upon the mother ship is laid and buried at the same time upon an under-water surface in a so-called simultaneous burying method, the operation can be conducted at a high efficiency; however, in a case the cable has a fault and after the faulty portion is pulled up on the ship for repairment, when the burying operation should be resumed, since both ends of the faulty portion have been already buried in sea bed and the positions thereof have been fixed, the burying device has to be guided accurately so as to align with the position from which the portion has been pulled up. This presents the necessity to provide a special ship with excellent operational performance on the waters where severe operational conditions prevail. In a shallow water, it is difficult to use a mother ship having a sufficient towing power.